Forming method and machine

ABSTRACT

This disclosure relates to the forming of workpieces in a plurality of steps at a plurality of forming stations. The workpieces are carried by recirculating fixtures and intermittently advanced along the work stations. At the work stations, the fixtures are located and held, and a forming operation performed on the workpieces while in the fixture. The fixtures are then advanced to the next work station and the foregoing steps repeated until the workpieces are completely formed and then discharged from the fixtures.

May 1, 1973 United States Patent [191 Motzer et a1.

FOREIGN PATENTS OR APPLICATIONS [54] FORMING METHOD AND MACHINE 3,452,693 ...ll3/ll3R [75] Inventors: Alfred E Mower Madden; Henry 3,439,520 4/!969 Zollinger, Jr., Cheshire, both of Conn [73] Assignee: Hobson and Motzer, Wallingford,

1/1957 Germany.r........................ ....72/422 Primary ExaminerRichard J. Herbst AttorneyDelio & Montgomery Conn.

[22] Filed: Apr. 29, 1971 [21] Appl. No.: 138,710

g of workpieces in y of forming stations.

The workpieces are carried by recirculating fixtures and intermittently advanced along the work stations.

At the work stations, the fixtures are located and held,

and a forming operation performed on the workpieces [56] References Cited while in the fixture. The fixtures are then advanced to the next work station and the foregoing steps repeated until the workpieces are complete l discharged from the fixtures,

y formed and then UNITED STATES PATENTS 7/1970 Connor.................. ....72/405 15 Claims, 12 Drawing Figures Patented May 1 1973 6 Sheets-Sheet 2 y d l INVENTORS S (Wm m w Mm A eww A A m U w W? Hp w,

ii. ill.

' Patented May 1, 1973 6 Sheets-Sheet 5 BY 9 M9 ATTORNEYS Patented May 1, 1973 7 7 3,729,977

6 Sheets-Sheet 5 INVENTORS FORMING METHOD AND MACHINE This invention relates to forming machines, and more particularly to forming machines of the type where a workpiece is transported through a plurality of forming stations.

Various types of forming machines including progressive dies and transfer presses have proved quite successful in many applications. However, in the forming of some workpieces from base stock to a finished piece through a multiplicity of steps the transfer of individual pieces from one forming station to another is not feasible. In some instances, specialized machines have been provided in which a workpiece is held and then acted on by a plurality of forming tools either while the workpiece is stationary or rotated in a fixture to present the workpiece to successive tools. In the progressive dies, the workpieces are generally progressively formed in a ribbon with the excess joining parts later out therefrom as the individual pieces are separated. This produces a substantial material waste, even though the transfer of the workpieces is facilitated by the joining thereof.

These various types of forming machines have proved quite successful in many applications. Each has generally proven itself for particular typesof workpieces.

However, in many applications where high precision, rapid transfer, and high volume production is required, these presently known forming machines have not been able to perform as efficiently as with other types of workpieces. An example of this are small workpieces, such as wire terminals. It is virtually impossible to provide a transfer mechanism to grasp and properly position wire strips through a multiplicity of forming operations. Such terminals may be more efficiently formed in progressive dies where the terminals are formed in interconnected ribbon fashion. However, there may be as much as a 400 percent material waste. Such workpieces may also be formed in so-called wire forming machines where the workpiece is held while successive forming operations are performed thereon. With this type of machine, the production rate is not high, and also the obtainable tolerances may be greater than desired.

Accordingly, the present invention provides a new and improved method and apparatus for forming workpieces in a plurality of operations which allow high production rates with high precision while holding material wastage to a minimum. Briefly stated, the invention may be practical in apparatus which in one form thereof comprises an endless conveying means having workpiece-receiving fixtures thereon which move along a plurality of forming stations. The fixtures are indexed to the stations and a movable member carrying forming tools or actuating members for tools at the work stations then causes a plurality of workpieces to be progressively formed as the fixtures are successively indexed. The conveyor is intermittently driven in one direction through a unidirectional clutch which is released just prior to a forming operation and positioning means properly locate and hold the fixtures just prior to forming.

An object of this invention is to provide a new andimproved forming method and apparatus therefor.

Another object of this invention is to provide a new and improved apparatus for forming articles in a plurality of successive forming steps.

Another object of this invention is to provide a new and improved method of supporting and transporting a plurality of workpieces to successive forming stations.

A further object of this invention is to provide a new and improved method and apparatus for accurately indexing and positioning workpiece-carrying fixtures through a plurality of successive forming stations.

The features of the invention which are believed to be novel are particularly pointed out and distinctly claimed in the concluding portion of this specification.

The invention, however, both as to its organization and operation, together with further objects and advantages thereof may best be appreciated by reference to the following detailed description taken in conjunction with the drawings, in which:

FIG. 1 is a front elevation of a press in which the inventions may be embodied;

FIG. la is a rear elevation of the press of FIG. 1;

FIG. 2 is a view seen in the plane of lines 2-2 of FIG. 1a;

FIG. 3 is a view seen in the plane of lines 3-3 of FIG. 121;

FIG. 4 is a view in section seen :in the plane of lines 4-4 of FIG. 2;

FIG. 5 is a view in section seen in the plane of lines 5-5 of FIG. 2;

FIG. 6 is a sectional view seen in theplane of lines 6-6 of FIG. 5;

FIG. 7 is a view in section seen in the plane of lines 7-7 of FIG. 2;

FIG. 8 is a view in section seen in the plane of lines 88 of FIG. 2;

FIG. 9 is a representation of a drive member utilized in the structures shown in FIGS. 1, la and 2.

FIG. 10 is a view partly in section of an operational forming drive; and

FIG. 11 is a representation of the method of successive forming of a workpiece in accordance with the invention.

As will hereinafter be described in detail, workpieces are inserted into fixtures on an endless conveying means as the fixtures are indexed to a station where the stock is partly inserted into the fixture and a workpiece severed or otherwise removed therefrom. The fixtures work workpieces therein are intermittently driven past a plurality of forming stations which act essentially simultaneously on all workpieces. Just prior to the forming operations;the fixtures are properly positioned and held in position during the forming. A suitable apparatus for performing the foregoing is now described with initial reference to FIG. 1. i

A press 10 may be used for operating the forming mechanism of the present invention. The press 10 comprises a frame 11 having upstanding pairs of side support members or columns 12 and 13. The ram 14 is reciprocated vertically as by means of connecting rods 15 and 16, joumalled at their lower ends to pins 17 and 18, respectively, carried by ram 14 and connected at their upper ends about the cranks or throws l9 and 20 of shaft 21. Shaft 21 is joumalled in frame 11 and carries on the end thereof a pulley 22 which is driven by belts 23 from a pulley 24 on the shaft of a motor 25.

Power is taken from shaft 21 from a crank 26 to which is connected a rod 27, also connected at its other end to a lever 28 on a shaft 29. Crank 26 and lever 28 are arranged such that rotation of crank 26 produces a rocking action of shaft 29. The shaft 29 intermittently operates a sprocket 30 having a chain 31 through a one-way drive mechanism as hereinafter more fully described A forming mechanism embodying the present invention is mounted in two parts to the bed or bolster B of the press and to the undersurface of the ram 14.

Reference is now made to FIG. 2 which shows a plan view of the lower assembly 32 on bolster B. A sprocket 33 is mounted to a shaft 34 which is intermittently driven through the endless chain 31 from sprocket 30. Mounted on shaft 34 below sprocket 30 (FIG. 4) is a conveying means in the form of a similar sprocket 35 which receives an endless chain 36 thereabout. At the other end of the lower assembly 32 is a shaft 37 receiving a sprocket 37a thereon about which chain 36 passes. Each link or selected links of chain 36 carry thereon workpiece-receiving fixtures 38. The lower assembly 32 includes a base member 39 received on bolster B on guide or locating rods 40. The shafts 34 and 37 are carries by the base member 39.

The chain 36 through the sprocket 35 (not shown in FIG. 2) is successively indexed past a workpiece blanking or cutting station, generally indicated at 41, where in the form illustrated it receives sections of Wire stock cut from strips W1 and W2. The strips W1 and W2 have a predetermined length thereof fed to station 41 through roller assemblies 42 and 43, a piston or solenoid 44 and workpiece gripping member 45. When the member 44 is a solenoid it may be energized upon predetermined position of the ram to cause gripping member or slide 45 to advance the stock W1 and W2 a predetermined distance. The station 41 may comprise a cutting and forming die disclosed in copending application Ser. No. 117,942 filed Feb. 23, 1971. This die inserts stock into the fixtures 38 and severs a workpiece P therefrom while forming an end thereof.

Referring to FIG. 5, a length P of strip W2 is inserted into a fixture 38 as it is indexed to a work-receiving position and held therein by pilot pins 46 and 47 which extend into pilot passages or holes 48 and 49 in each fixture 38. The pilots 46 and 47 are on a reciprocating member 50 which will move the pins upwardly from the broken line position to the full line position as viewed in FIGS. and 6. Member 50 is moved by a solenoid or piston (not shown) as the fixture 38 is indexed into position. As shown, the member 50 carries two forward pilots 46 and two rear pilots 47 and engages two adjacent fixtures 38. As shown in FIG. 6 each of the forward pilots 46 engages a fixture 38. Each of the carriers 38 contains workpiece-receiving slots or passages 51 into which the workpieces P are inserted from stock W1 and W2. A cover guide plate 53 which extends over the path of the fixtures 38 also has pilot holes 54 therein for reasons hereinafter made apparent. As will hereinafter be more fully described, each time the chain 36 with the fixtures thereon is indexed a drive clutch is released and then when the pilots 46and 47 or other pilots hereinafter specified are inserted into the pilot holes of the fixtures 38, the fixtures with the workpieces therein will be properly positioned for a forming operation. The pilots, in entering the passages with rounded ends may engage the fixtures 38 and produce small movement thereof, with the drive disconnected to properly locate the fixtures. The upper assembly 55 will act on an operating member 56 of cutting and forming station 41 to sever a workpiece P, after one end has been inserted into a fixture 38. The workpiece will be cut approximately along the line C as described in the aforementioned pending application.

As the fixtures 38 are indexed from left to right, as

shown in FIG. 2, they will pass along a plurality of forming stations generally indicated at 60 and then ultimately to a discharge hopper 61 where the workpieces may be dropped from the fixtures 38. A forming operation at some or all of stations 60 may be performed in cooperation with complimentary stations on upper assembly 55 as hereinafter described.

Reference is now directed to FIGS. 3 and 4 which show the upper assembly 55 on ram 14 and lower assembly 32 received on bolster B. The upper assembly 55 comprises a base member 63 having an elongated member 64 thereon which carries a plurality of pairs of pilots 65 and 66 adapted to be inserted through the pilot holes 54 in guide member 53 and also into the pilot holes 48 and 49 in fixtures 38.

Also carried on or defined in member 63 is a plurality of members 67, some or all of which may be forming and/or holding members arranged to cooperate with work stations 60, and actuating members 70, 71, 72 and 73. As hereinafter explained, the actuating members 73 may operate a forming member carried at one of stations 60.

FIG. 4 shows the section adjacent the cutting and loading station previously discussed with FIG. 5 and further shows a pusher mechanism 76 actuated by a roller 77 on member 70. As ram 14 comes down, roller 77 will engage the beveled surface 79 of pusher 80. Inward movement of pusher 80 will cause plunger 81 biased by spring 82 to engage a workpiece P to insure full insertion thereof into a workpiece passage 51. The fixtures 38 will move along the surface of a guide portion 83 of base member 39. Pusher member 80 is returned when member 70 with roller 77 thereon is raised by means of a return spring 84 acting on depending leg 85 of pusher 80. Spring 84 is disposed around the shank of a guide providing bolt 86 having a head 87 which may also act to limit outward movement of pusher 80.

Each of fixtures 38 is attached to a link of chain 36 by means of an arm 88 which is pinned at two points to each link and which overlies the rear portion of fixture 38. Fixture 38 has guide passages therein which receive two-part guide members 90 on each fixture. A threaded pin extends through portions 90a and 90b of the guide members which are received in the passages through the fixture 38. The lower portion 90b of the guide member is also received in a guide track or channel 91 defined in a block 92 carried by base member 39. Member 92 has a plurality of pilot passages 93 defined therein along the length thereof.

Reference is now made to FIG. 7 which exemplifies a forming step along one of a pair 60a, 67a of the cooperating stations 60 and 67. The forming members at 67a comprising parts 94 and 95 form an angle in workpiece P. While piece 94 holds the workpiece P against an anvil member 96 at station 60a, member 95 strikes the end of workpiece P and moves therealong to form a right angle end therein. Prior to the member 94 or 95 engaging the workpiece, the pilots 65 and 66 will enter the pilot holes through plate 53 and fixture 38 and secure the fixture 38 in the proper position for the forming operation.

Fig. 8 shows a further forming step on the workpiece P at a succeeding station. The station 67b of FIG. 8 including actuator 72 cooperates with station 60b on the lower member. When ram 14 with base member 63 thereon comes down the pilots 65 and 66 extending from block 64 will enter the pilot holes through guide plate 53 and fixture 38 will be properly located and held. A holding member 97 engages workpiece P on an anvil member 98 while a sliding forming member 99 carried in a guide 100 is moved inwardly in a forming stroke by actuator 72 as it strikes the beveled edge 101 of slide 99. When actuator member 72 moves upwardly on ram 14, member 99 is returned to a rest position as by means of a spring 102 which has been placed in compression between the head 103 ofa bolt 104 and a block member 105 mounted to base 39. Bolt 104, as shown, is threadably received in slide 99. As shown in FIG. 2, the bolts 104, springs 102, etc., may be in pairs.

After the forming step of FIG. 8, when ram 14 rises, the chain 36 will be indexed and the fixtures 38 moved to succeeding work stations. The various stations to which the fixtures 38 are indexed may perform a forming operation on the workpiece directly as shown in FIG. 7, from the vertical direction or may actuate a forming member to move horizontally with respect to movement of the ram as shown in FIG. 8.

Other forming members generally designated by the reference 60, may take any convenient form dependent on the desired working stroke on the workpiece. As shown in FIG. 2, the actuator 73 at station 60c may operate on a first forming slide 107 having return springs 108, and also actuate another forming slide (not shown) upon engagement of members 109. The second forming slide is returned by springs 109a on guide bolts 109b.

It is also to be understood that where desired, a forming member may be actuated from below. As for example, in FIG. 10, an auxiliary drive shaft 110 powered from the main drive shaft has a cam 111 thereon adapted to operate a camming member 112 to actuate a forming slide 113 carried in a guide 114. A return spring, not shown, is provided for member 112. Thus, the forming members may be actuated from either direction. The selection of the type of forming members carried either on the member 39 or below the bolster B, or on the ram 14 will, of course, depend on the type of the workpiece that is being formed, the shape that is to be imparted thereto, and the type of press or other powered member which is utilized. These are merely design considerations.

The chain 36 with fixtures 38 thereon may be driven by a drive as shown in FIG. 9. A unidirectional clutch 116 is driven in a forward direction by rod 27 as crank 26 is driven downwardly. The clutch 116 is rendered inoperative as crank 26 moves upwardly and the outer sleeve 117 of clutch 116 slips with respect to the inner shaft 118. A preferred clutch is one known as a Form Sprag manufactured by Form Sprag, 2360l Hoove Road, Warren, Michigan. Shaft 118 drives sprocket 30 through gearing 119 and an electric clutch 120. Clutch 120 is de-energized when a switch. 121 is opened by an actuating member, as ram 14 descends. This disconnects the chain 36 from the drive. As the round ended pilots enter the pilot holes in fixtures 38, they will give any small position adjustment movement necessary to bring the fixtures into properly aligned position for the forming operations, and also hold. the fixtures in such position.

It will further be apparent that with the recirculating fixture type forming mechanism shown, both sides of the chain belt drive may be utilized for forming purposes to, in essence, provide two forming machines. This is indicated by the severing mechanism 41 shown in broken line in FIG. 2, and the members 67' and pilots and 66 in FIG. 3.

FIG. 11 illustrates a typical workpiece which is known as a wire wrap terminal, and the various progressive forming steps that are made as the fixtures 38 in which the workpieces are carried progress along the die. The end of the workpiece inserted in the fixture is not shown. All of the stations 60 need not be used for forming purposes. Some may be utilized for gaging or positioning; as exemplified in FIG. 4.

The seven forming steps are performed as the workpiece, a rectangular wire, advances between the complimentary stations 60 and 67. Other operations such as cutting, slitting, swaging, etc., may be performed. Where desired, the forming tools may also be arranged to perform a drawing operation.

The invention is adaptable to form various workpieces, and may take various forms and sequences of operation dependent on the workpiece to be formed and the type of press or other powered operator available. The locating and holding devices exemplified as pilots 46, 47, 65 and 66 may be located either above or below the fixtures. For example, the pilots 46 and 47 are operated from below by a solenoid operated by a switch from the ram prior to the pilots 65 and 66 engaging fixtures. This is done because the cutoff and end forming fixture 41 is actuated prior to the other forming operations. Similarly, others of the forming members suchas the slides and 99 might be operated slightly before or after the other forming members, either from above or below, as by a piston or solenoid mounted to the lower assembly 39, or bolster B. Any given position of the ram may be utilized as a reference point for actuating a piston, solenoid or other force producing, or timing device.

From the foregoing it may be seen that the objects of the invention set forth as well as those made apparent are efficiently attained. While preferred embodiments of the invention have been set forth for purposes of disclosure other embodiments of the invention as well as modifications to the disclosed embodiment which do not depart from the scope of the invention may occur to others skilled in the art. Accordingly, the appended claims are intended to cover all embodiments and modifications of the invention which do not depart from the spirit and scope thereof.

What is claimed is:

l. A forming apparatus comprising first and second members relatively movable toward and away from each other and having a plurality of complimentary forming tools thereon defining a plurality of forming stations, an endless conveyor passing said stations, a plurality of workpiece holding fixtures carried on said conveyor in spaced relation and movable with said conveyor past said stations on a first of said members to successively present workpieces to said stations while the workpieces are in said fixtures, means for intermittently driving said conveyor to move said fixtures from station to station, means for relatively moving said members to operate said stations, and means carried by at least one of said members for locating and holding said fixtures as said members are moved to operate said stations.

2. The forming apparatus of claim 1 wherein said fixtures guidably move on said first of said members which is stationary, and said locating means are carried on the second of said members which moves towards and away from said first member.

3. The forming apparatus of claim 2 wherein said fixtures have passages therethrough, and the second of said members carries pilot pins adapted to enter said passages prior to a forming movement by said second member.

4}. The forming apparatus of claim 3 further including means for disconnecting said conveyor drive means prior to a forming operation.

5. The forming apparatus of claim 2 wherein guide means for said fixtures are provided on said first member and each of said fixtures are guided in said guide means past said work stations.

6. The forming apparatus of claim 2 further including means for inserting work stock into said fixtures and cutting workpiece blanks therefrom prior to said formin g stations.

7. The forming apparatus of claim 2 wherein said conveyor moves in linear paths in opposite directions and forming stations are provided along each of said paths.

8. The forming apparatus of claim 2 further including means movably mounted with respect to said stationary member for operating at least one of said stations.

9. The forming apparatus of claim 3 wherein said conveyor drive means includes a clutch which is disengaged prior to a forming operation, and said pins upon engaging said fixture passages may move said fixtures.

l0. Forming apparatus comprising first and second members movable relatively toward and away from each other, an endless conveying member mounted to one of said members, a plurality-of workpiece holding members carried in spaced relation along the length of said conveying member, at least one forming member carried on said second member constructed and arranged to move toward said first member, means on said second member for engaging and clamping said holding members upon relative movement of said members, additional means on said second member for driving at least one of said forming members toward said workpiece holding members, and drive means for moving said conveyor member, said press members, and said forming members in timed relation to advance said conveying means, clamp said holding members and actuate said forming members.

11. A forming apparatus for progressively forming workpieces comprising a base member and a second member movable toward and awa from said base member, a plurality of forming tools efimng a plurality of forming stations on said members, an endless conveyor on said base member passing said stations, a plurality of workpiece holding fixtures movable with said conveyor past said stations to successively present workpieces to said stations, said base member defining a path for movement of said fixtures along said stations, cooperating fixture guide means on said fixtures and said base member, means for intermittently driving said conveyor to present workpieces in said fixtures to said forming stations, means for operating said forming stations to produce a forming operation on said workpieces in said fixtures, and means for locating and holding said fixtures at said forming stations prior to operating said forming stations.

12. The forming apparatus of claim 11 wherein said conveyor comprises a chain having a plurality of links, connecting means attaching said fixtures to links of said chain, said connecting means including said guide means and said fixtures.

13. Apparatus for progressively forming workpieces at a plurality of aligned forming stations, comprising a first member, a plurality of aligned forming stations at least partially defined on said first member, a second member movable toward and away from said first member, said second member carrying means for actuating and cooperating with said forming stations to produce a forming operation on workpieces thereat, a chain belt conveying means on said first member comprising a plurality of links, a plurality of workpiece holding fixtures, means connecting said fixtures to said links in predetermined spaced relation, fixture guide means defined on said first member, cooperating guide means on said fixtures for guiding said fixtures in a predetermined path along said forming stations, means for moving said second member toward and away from said first member to produce a forming operation, means for driving said chain belt, means responsive to movement of said second member toward said first member for disconnecting said belt drive means, and means carried by one of said first and second members for locating said fixtures when said chain belt drive means is disconnected.

14. The apparatus of claim 13 wherein said cooperating guide means are carried on said connecting means.

15. The apparatus of claim 13 wherein said locating means comprise pilots carried by said second member adapted to engage said fixtures. 

1. A forming apparatus comprising first and second members relatively movable toward and away from each other and having a plurality of complimentary forming tools thereon defining a plurality of forming stations, an endless conveyor passing said stations, a plurality of workpiece holding fixtures carried on said conveyor in spaced relation and movable with said conveyor past said stations on a first of said members to successively present workpieces to said stations while the workpieces are in said fixtures, means for intermittently driving said conveyor to move said fixtures from station to station, means for relatively moving said members to operate said stations, and means carried by at least one of said members for locating and holding said fixtures as said members are moved to operate said stations.
 2. The forming apparatus of claim 1 wherein said fixtures guidably move on said first of said members which is stationary, and said locating means are carried on the second of said members which moves towards and away from said first member.
 3. The forming apparatus of claim 2 wherein said fixtures have passages therethrough, and the second of said members carries pilot pins adapted to enter said passages prior to a forming movement by said second member.
 4. The forming apparatus of claim 3 further including means for disconnecting said conveyor drive means prior to a forming operation.
 5. The forming apparatus of claim 2 wherein guide means for said fixtures are provided on said first member and each of said fixtures are guided in said guide means past said work stations.
 6. The forming apparatus of claim 2 further including means for inserting work stock into said fixtures and cutting workpiece blanks therefrom prior to said forming stations.
 7. The forming apparatus of claim 2 wherein said conveyor moves in linear paths in opposite directions and forming stations are provided along each of said paths.
 8. The forming apparatus of claim 2 further including means movably mounted with respect to said stationary member for operating at least one of said stations.
 9. The forming apparatus of claim 3 wherein said conveyor drive means includes a clutch which is disengaged prior to a forming operation, and said pins upon engaging said fixture passages may move said fixtures.
 10. Forming apparatus comprising first and second members movable relatively toward and away from each other, an endless conveying member mounted to one of said members, a plurality of workpiece holding members carried in spaced relation along the length of said conveying member, at least one forming member carried on said second member constructed and arranged to move toward said first member, means on said second member for engaging and clamping said holding members upon relative movement of said members, additional means on said second member for driving at least one of said forming members toward said workpiece holding members, and drive means for moving said conveyor member, said press members, and said forming members in timed relation to advance said conveying means, clamp said holdiNg members and actuate said forming members.
 11. A forming apparatus for progressively forming workpieces comprising a base member and a second member movable toward and away from said base member, a plurality of forming tools defining a plurality of forming stations on said members, an endless conveyor on said base member passing said stations, a plurality of workpiece holding fixtures movable with said conveyor past said stations to successively present workpieces to said stations, said base member defining a path for movement of said fixtures along said stations, cooperating fixture guide means on said fixtures and said base member, means for intermittently driving said conveyor to present workpieces in said fixtures to said forming stations, means for operating said forming stations to produce a forming operation on said workpieces in said fixtures, and means for locating and holding said fixtures at said forming stations prior to operating said forming stations.
 12. The forming apparatus of claim 11 wherein said conveyor comprises a chain having a plurality of links, connecting means attaching said fixtures to links of said chain, said connecting means including said guide means and said fixtures.
 13. Apparatus for progressively forming workpieces at a plurality of aligned forming stations, comprising a first member, a plurality of aligned forming stations at least partially defined on said first member, a second member movable toward and away from said first member, said second member carrying means for actuating and cooperating with said forming stations to produce a forming operation on workpieces thereat, a chain belt conveying means on said first member comprising a plurality of links, a plurality of workpiece holding fixtures, means connecting said fixtures to said links in predetermined spaced relation, fixture guide means defined on said first member, cooperating guide means on said fixtures for guiding said fixtures in a predetermined path along said forming stations, means for moving said second member toward and away from said first member to produce a forming operation, means for driving said chain belt, means responsive to movement of said second member toward said first member for disconnecting said belt drive means, and means carried by one of said first and second members for locating said fixtures when said chain belt drive means is disconnected.
 14. The apparatus of claim 13 wherein said cooperating guide means are carried on said connecting means.
 15. The apparatus of claim 13 wherein said locating means comprise pilots carried by said second member adapted to engage said fixtures. 